Telephone system



May 18, 1943v M.' E. MALoNEY Y l TELEPHONE SYSTEM -4 Sheets-Sheet l //v VEA/TOR M. E. MALONEV AoRA/EV m. QQ

M. E. MALONEY TELEPHONE SYSTEM May 18, 1943 Filed April l2, 1941'` .4 Sheets-Sheet 2 New .Ulu

/A/I/EA/TOR M E MALONEY A 7' TURA/EV May 18, 17943 M. E. MALONEY 2,319,424

TELEPHONE SYSTEM` Filed April 12, 1941 4 Sheets-Sheet 3 /N VEN 725%? @y 5 MA1. /vEr A T T ORA/Es/ Mgy 1s, 1943 Filed April l2, 1941 M. E. MALONEY l 2,319,424

TELEPHONE SYSTEM i' 4 Sheets-Sheet 4 A 7' TOR/VE V Patented May 18, 1943 UNITED STATES PATENT TELEPHONE SYSTEM Martin E. Maloney, Flushing, N. Y., assignor Ato Bell Telephone Laboratories, Incorporated, New York, Y., a corporation ofjNeW York Application April 12, 1941, Serial No. ;3$8,j22 1 6 Claims. (Cl. 179.-s27) This invention lrelates to telephone systems and more vparticularlyto those systems in Whichthe numerical indication of a callingline is automatically determined and made available.

VIt is well known that, in certain types of rvtelephone `connections such as those, -for example, in which a calling station is extendedautomatically orotherwise to some remote station, it is sometimes necessary to ascertain the number of saidcalling station in order that charges for the .call therefrom may be properly assessed thereto.

`Such .connections are known as toll or long distance connections and, in some types ,of Iautomatic telephone systems in which the calling station is routed to its destinationthroug-h the position of ay recording operator, thelnumber of the calling station is Verified 4manually by the operator Who,iafter orally ascertaining the num- .ber from -the ,calling subscriber, checks ,it -by touching the -tip ofra so-calledchecking cord to Va pin in a check multiplefwhich -isassigned -to the given number.

If `,the ,number as `given by the calling vparty is correct, a tone lcircuit will 4be completedvover thechecling cord and pin and the tone isheard in theoperators telephone set. On -the other hand, if the .number as givendoes Vnot 4correspond to that of the `pin lto` Whichthe ,tip of-the cordhas been touched, the tonecircuit eisinot completed andthe tone is not heard, a fact which indicates 4to the .operator that the `number given bythe calling vpartydoes `not cor,- lrespond to that of .the station from which he is calling andrservice may then `loeV denied Huntil Ithe discrepancy is rectified.

In automaticV telephonesystems, it desirable `to have the identity ofthe callingfstation ascertained and transmitted .automatically to 'some -point at 4which it may be recorded "on settable` -.registersfor the Visual display of thenumber, if nthecall is completed throughV an operatorsposition, Vor foi-,automatically `recording the number if the information is to beyutilized for operating printing or other recordingr devices responsive to-thesettingof the registers. A

VMy invention is principally concerned Withithc so ,mies imeaonofthe.

the line, Qiruiisare siclxnletdhstwsp the resistersand the @11u91 enormes 0f .th dei'z'ce that will @euse theregisters ,t beset tiifgciance .with the numeri@ dsignation 9h Pli lre- The .Settnsff theresisteis "thn .he Filmed,

of (nurse, 1n ,any rmanner ,desired as, rfor instance, Operating ,a print" v,a bank of lamps Qrtra the registers to a 10 A adapted Ato-,utilize the ,y n

its function.

Another V,feature .of .the 4invention is ,a 4knovel .arrangement @f the main electrode .Qf' .the sasfilled device to determine XI iarty line identificaytionl should the -t leph ne oflice :to which Ithe invention may beapplied include two-party lsta,- tons upon the same line tfor eachrof tyvhichian identification would be -nefssary on calls crisi? rating `from 4each one 0f the' sta'tibns! ,In fac,-

cordance `Withthis feature-of theinvention, Ione 2,5 tion originating `rtliencjall.

,GCO ding tenpthsrffsauirs pffthe `ihrs-@IciQn means are` provided :vrlnereby the intenta "n -may `be utilized .in commonvby .tivopr more'telephone f umts t0 provide Ine identificati@ t0-ribs @S- 'Menthe-.invention ris edsptsdQr-suq .fsentheelsitend ,19e of each line in Lea1 Qicefisproyidedtwithkan additional control electrode V)fer ofIice :identifica- $19.11 fvurpQSeS--aid `the ,resister Qz1nstsb1-t0 `table means forfresponse t-eilices ,and in whichthe electronic devicesfein- Y4o tnelstations .of a uraltyof idoo'uneteiepnone type .vvell knorvn iintheeart, which break v I connectable to a suitable source of potential through a relay of a settable register. When the station initiates a call, a source of positive potential is applied over that conductor of the line to which the main anode of tubes individual to the calling station is connected, and the difference of potential between that applied to the cathode vand that applied over the lline to the anode will cause the tube to break down and become conducting, not only in the space between the cathode and main anode but also between the cathode and the control electrodes since the latter are also connected to a source of positive potential through the connectable relays of the settable register. Obviously, these relays will operate and since there is one connected to each control electrode, the operated relays indicate the calling line designation.

As said before, the operated relays of the register may be utilized in any desired manner. Their setting, for instance, may be utilized to provide a record or visual display of the calling line number, or the setting itself may be transmitted to a local or distant register sender for the purpose of controlling, ticketing equipment thereat. In other words, the manner in which the registration is utilized, being no part of this invention, may be adapted for whatever purpose is indicated by the character r function of the telephone system to which the invention may be applied.

`A clearer conception of the scope and purpose of the invention may be obtained from the following description taken in connection with the appended claims 'and attached drawings in which: A Fig. 1 shows a typical line of a telephone olce, said line having two stations thereon, each provided with a gas-iilled tube device, a switching train including a diagrammatic showing of a so-called ticketing truck which may form a part of a connection for a call involving calling line identification, terminal punching facilities for cross-connecting the control electrodes of the various line tubes, and a portion of a connecting relay by which said electrodes may be connected tothe relays of a settable register;

` Fig. 2 shows the terminating end ci the tici;- eting trunk, the remainder of the terminal punching 'facilities andthe remaining portion of the connecting relay the function of which may be controlled in any suitable manner;

Figs. 3 and 4 show the settable register; While Fig. 5 shows how Figs. 1 to 4, inclusive, should be', disposed Vrelative to `each other in order to disclosethe invention completely.

Referring now to the drawings, there are provided, as indicated therein, f two stations upon ,one line, namely, station 1098 known as the "tip party having its ringer1 connected to the tip conductor'and to ground, .and station 8190 known as the ring party having its ringer bridged across both the'tip and ring conductors of the line. Since there are twov stations upon the line,

a gas-lled tube is 'provided for each station,

there being a similar tube `for each station in other lines or, if there is but one station to a 'line as would be the case for so-called individual lines, then one such tube would be provided for each such line. As shown in the drawings,y the two stations may be assumed to have numerical designations 8190 and 1098 as before mentioned. In the ordinary'automatic telephone exchange, the line to which the stations are connected would be disposed upon the terminalsof a linefinder bank to which suitable line-.finder switches LE' would have access whenever a call is initiated thereover, and the connection would then be extended under control of dial pulses over a train of selectors such as, for instance, a rst selector (1st sel), a second selector (2nd sel), a third selector (3rd sel) etc. to the terminals of the desired station.

Each tube individual to th-e station (or line) has a main anode connected to the line, there being a condenser-'resistance network connected thereto in the event that the same may be necessary to prevent false operation of the tube on ringing current, although the same may be dispensed with if thevalue of the ringing voltage permits. Thus, tube A associated with station 1093 has its anode connected through resistances 04 and |05 and conductor E01 to the ring conductor R, the mid-point of said resistances being connected through a condenser 09 to ground, while the tube B associated with line S has its main anode connected through resistances I 0I and H12 and conductor iil'l to the ring conductor R, the mid-point of said resistances being connected through condenser E03 to ground. In the same way, the main anode of the tubes of all other lines or stations regardless of whether they are tip stations, ring stations or individual line stations are connected t0 the ring conductors R of such lines through suitable condenser-resistance networks if the same are rendered necessary by the use of high ringing voltages. Otherwise they are connected directly to the ring conductors R.

Each of the individual tubes has a control electrode for each digit or character of the station identification. If, for instance, the station is individual to the line and all it has for identication purposes is its numerical designation, then for a 10,000 line oice, its line identication tube would have four such control electrodes, one for each digit of the line identification. On the other hand, if the station in question happens to be on a party line station as those illustrated in the drawings, no control electrode would be necessary to identiiiy the party since such identification co-uld ordinarily be provided through the accounting clrice of the operating company. Yet, if a record or display of such party identication is necessary, then an additional control electrode Ashould be provided as shown in the drawings. Also, if the various lines in the telephone olice are entitled to different classes of service, there would be another electrode to indicate such class, and where two or more oces use the common equipment of the invention, by which is meant a common settable register and a common connecting means whereby such register is connected to the electrodes of the line tubes, it would be necessary to indicate in which of the offices the calling line is located, in which event, there would be, ci course, ano-ther control electrode to indicate the oce;

The control electrodes of all the line tubes are suitably extended to a `terminal punching TP whence they are distributed individually to seven other terminal punchings, namely, a punching PTY having a terminal W and a terminal J to either of which is connected the electrode designating the party,V a punching IPTH having ten terminals reserved for the thousands designation to one of which is connected the electrode designating the thousands digit of the line, a hundreds punching LPH having ten terminals reserved for the hundreds designation to the proper being made through a v `"which may be operated 'in .any'suitablemanner asignar terminal of which isconnect'ed the electrode designating `the hundreds digit, ja tens punching LPT and a units punching LPU each having 'ten terminals reserved for tens and units designa'- tions, respectively, to a terminal Aofeach of 'which are connected the two respective electrodes des. ignating such digits, a class punching LPC hav ing as many terminals as there are classes and 'to the proper terminal of which is connected the `electrode designating the class, and an ofdce terminals punching LPO Lhaving Aas many terminals `as there are -oflices using the `common equipment, and to the proper `oiiice terminal of which is connected the electrode of the line tube reserved for the cnice designa-tion. The -terminalpunchings are, of course, common to 'all linesfas indi cated by the `vertical,conductors extending from the `punchings and to which the electrode 4conductors are connected.

As an example of the distribution Vof the elec- Y 'trodes, consider the tube B associated with station `8190. Assume, further, that the line is V1a party line, that it has a four-digit numerical designation, that it is lentitled to a particular class of service, and that the identifying `equip-- ment shown in Figs. 3 and 4, is used in kcommon by two offices. The tube, therefore, would have Vseven control electrodes which are so indicated, vand they are connected tov Va `primary terminal `punching TP whence they are distributed to the n,

seven terminal punchings 'PTY- LPOin the following order: Electrode I is reserved rfor 'party Adesignation and since the `station is a ring or a J` station, said lelectrode would Vbe"connected to terminal J on punching PTY; electrode 2 is y reserved for `the thousandsV digit and would be v connected to terminal 8 von punching LP'IAH; electrode 43 is reserved for "the hundreds digit` and would be connected tojtermina-l "I on punching LPH; electrode 4 is reserved for the tens 'digit and would be connected to'terminal B on pun'ch.-

ing LPT; electrode 5 is reserved for the units digit land would be connected to terminal 0 on punching LPU; electrode 6 is reservedfor "the class ,of service designation and would be "cone nected to whatever terminalon punching LPC is reserved for this class, while electrodel lr'eserved for the oiiice, would be wired Ato the terminal I or 2 on punching LPO` depending upon which of these two numerals designates the oliice containing the line. The wiring` distribution e of the electrodesof tube'A assigned to station T1098 is "similarto that of tube B andinay be easily followed on the drawing `'from the above example. y

The number of electrodes .supplied "for'ihdication purposes is thus fa functin o'fthenuiber may be `increased or reduced in` accordancewith the variation in the 'number of such characters. Thus if no record of the "indication oftheparty designation is required, Athe same being `availalale Strom the accounting records of the operating company, electroder "I m'ay'be "omitted as'Will also tbe the case where no 'ofcelindicatin' 'would be required, "in which event electrode lfwouldjbe "'mitted.

'The present embodiment of the intentionfis adapted, by way of illustration,` merely'tofopefrfate a setta'ble` register and, afprinting device in Figs.'3 and 4, connectin `to,thefformer muiticoritact relaycvoNN shown tand 'by'which the control electrodes are lconnectent@ "the registerandthe signaiing'conducof separate identifying characters of the lineand tors `are connected to the trunk. This the simplest of the many variety of formsjw'hich the invention may take as it is obvious `that the register and the connecting and controlling means :may form parts of other circuit systems which may be adapted to control the sequential per-h formance of the essential control and line identifying operations described hereinunder.

Considering, now, Figs. 3 and f4, the armatures to the left of relay CONN, `except armatures `a and b, are connected to the operating windings of the various register relays. The calling line number register comprises ten relays for each of the digits'to be identiiied, namely, the thousands register comprising relays THU-THS, the hundreds `register comprising relays Htl-H9, the tens register comprising relays TIL-T9, the units register comprising relays U0U9. The party register comprises relays J and W (if the same is necessary), the class register comprises as many relays CII- C9 as there are 'classes of service, and 'the oiiice register comprises 'relays OFll-OFS to indicate each of the ofces in which `a line may be located. Each relay in each register is double Wound with one of the windings connected, 'as said before, 'to an armature of the multicontact relay CONN, said connections being made consecutive in order to group the relays at each `registerjwith those electrodes of the various line tubes which identify the digit or character reserved'for the register.

The'register `relays are provided with a lock- 'in'g circuit over conductor 301 'to ground on the contacts of a relay 416. Each of the relays is provided, also, with an appropriate number of contact pairs, the armatures of which are V*all grounded so that when the relay operates, it applies ground via the vcontacts of a cut-in relay to ve conductors ,300 to 304, inclusive, in the appropriate combination called forby the following code 'to indicate the digit or character designated by the operated relay in the registers. Each register relay 'i-s further provided with one contact pair with grounded armature which usupplies Vgroundto conductor 309 for operating "start relay S'I'I for a .purpose Aset'forth hereinafter.

Table of icodes.

Conductors Dig The groups of ve 'conductors'SQ'O-Sl, inclusive, vof each register are extendedto the magnets `(not 'shown 'ofjany commercially available printer 406. Thus' the left 'front c'ontacts of the `partyV relays v and W are 'connectedfto 'the armatures Aof relay VP'Pwhereby 'they may be connected with conductors A-3III I, 3);2`fand 304, those'oi the thou- Esands register are lc'or'ir'iectedto dthe armatillresbf 'relay TlI-I; those of the hundreds registerare 'connected to 1the armature "of relay 1H; those'of `the tens registers are vconnected to -the yarmaiturescf -relay T; those ofthe unitsregisterare lccnnectedjft-,o r the armatures 'fo'i Vrelay U, Athose Jof 'the 'class' relays are *connected to-*the armatures of relay CL while thosel of 4the oce register are connected tothe armatures of relay OFF.Y VRelays PT, TH, H, T, U, CL and OF are operated in cyclical order by vany suitable progresscircuit 40'| which rst operates relay PT toconnect conductors 30|, 302 and 304 to the contacts or relays J and W; then operates relays TH, H, T, U, CL and OF in the order named to connect, in succession,vv conductors 300-304 to the -contacts of each of the registers associated with the separate cut-in relays. Inasmuch as each/register will have one of its relays operated .at the time of the cut-through to the printer, as will be shortly described, the-two conductors in the register group which are grounded by said relay will cause the printer to operate and print'the digit designated by said grounded conductors.

Having described the structure and arrangement of my invention, its manner of operation will now be set forth in some detail.

In Fig. l is shown a schematic disclosure of the equipment at the originating ofce of an automatic telephone system of the so-called stepby-step type wherein switching selectors shown in the gure as line nder LF, rst selector, second selector, etc. up to and including the 'ticket- .ing trunk are usually settable directly in response to dial pulses from an originating station. In telephone connections involving the necessity of identifying the number of the calling station such as, for instance, long distance connections, the line may be routed through a third selector which is selectively positioned for connection with a ticketing trunk. If, therefore, the switching train reaches the third selector switch and this switch selectively connects itself to 'a ticketing trunk reserved for calls necessitating the veriiication of the calling line number, the calling line identification circuit of the present invention may be used to determine such number by oper-ating relay CONN by any 'suitable means.

We may now assume that station 8190 initiates a call which requires line identification. When the trunk selectors have been selectively positioned to engage a ticketing trunk over the third elector bank, relay CONN is operated and is iollowed by the operation of relay ST whose circuit may be completed over a set of contacts on relay CONN and controlled in any other manner desired. A positive source of potential is now connected to the ring conductor of the extended connection over a circuit which maybe traced from v.positive battery on the contacts of relay CK, up-

per contacts of relay ST, right inner contacts of relay CONN, conductor 20|, the ring conductor R ofthe extended connection, conductor |07, re-

sistance |02, resistance |0| to the anode of tube B. At the same time another path is closed from battery on the contacts of relay CK, lower contacts of relay ST, conductor 305 to the windings of all the register relays, preparing them for operation in the manner described hereinafter. Further, the grounded side of the battery on the contacts of relay CK is now applied through the upper back contacts of relay TP, conductor 40|, contact b on relay CONN, terrninal'marked b', to the cathode of all line tubes whose respective vstations are known as ring stations or as individual lines. Since it 'is assumed that the calling line is a ring station, the connection of positive battery to the ring of the calling line through its extended lconnection with the ticketing trunk and the vnegative side of said battery connected to its -cathode over contacts b of relay CONN, will ycause the tube of the calling line to breakdown and be rendered conductingbetween the cathode and the anode thereof which, as soon as it occurs, will cause conductivity to spread between the cathode and all of the control electrodes in the tube, eachof which is'now connected to a register relay having positive battery connected therethrough over conductor 305 as above described. In consequence of this conductivity over the control electrodes, circuits are completed thereover to such register relays. Thus over control electrode a path is completed from ground on the cathode, electrode I, terminal J on punching PTY, contacts on relay CONN, conductor 306, left winding of relay J to `battery on conductor 305. Relay J operates and locks over its right windingand right inner contacts, conductor 307, to ground on the contacts of relay M8 in the printer 406. Similar circuits are closed over appropriate electrodes for relay THB, for relays Hi, T9, and U0 all of which operate and lock over their respective right windings and inner contacts to ground on the contacts of relay 4|5. A circuit is also closed for the appropriate class relay which, in this case may be assumed to be relay C9, over the No. 6 electrode, and another circuit is closed for the appropriate oce relay, in this case assumed to be OFS, over the No. I electrode, which relays lock over their respective right windings and right inner contacts to ground on conductor 307. Hence the application of breakdown potential over the appropriate conductor of the calling line as extended thereto via the built-up connection, results in the operation and locking of a relay in each of the individual registers which identies the particular digit or character for which that register is reserved.

A`s.soon as a relay in each register is operated, a series circuit is completed for relay CK extending from battery through its winding, the right outer contacts of oflice relay OFS, serially through the right outer contacts or the class relay C9, and serially through the right outer contacts of each of the other relays in the Yindividual registers which have been operated, to ground over conductor 308 and the right outer contacts of relay J of the class register. Relay CK operates and disconnects `battery from the ring conductor R Vof the line and from the register relays, causing the tube to quench and the relays to restore to normal, concurrent operations having taken place in the meanwhile to record the station or line number.

, If the calling line happened to be station 1098, assumed to be the tip party station by virture of vthe fact -that its ringer is connected to ground,

front Ycontacts of relay TP, conductor 402, contacts aof relay CONN, terminal a ofthe punching, the cathode of tube A individual to station 1098, and, of course, to the cathodes ofallother tubes' having their` respective cathodes wired to terminal a. Should theloop be long and a relay TP like that shown is too insensitive to operate Vonthe diminished current, a more sensitive single'armature and contact relay maybe used. and

another relay operating ol said contacts may then be utilizedjto perform the local functions,

Tube A, however, is the only tube that breaks down land is; rendered conducting thereby since the positive potential `is applied over the extended connection of the calling station only to its own mainianode and to the anode ofV no other tube. 4The conductivepath is initially through its cathodeand, anode but almost immediately the conductivity is extended` to the control anodes thereof. As; withstation 8190, circuits are completed between the controlelectrodes of tube A and over the contacts of relay CONNto the various register relays, operating those which identify the various digits or characters of the calling line as explained with reference to said station 8190.

Returning now to the operation oi the register, it is evident that any settable device adapted to respond to the grounds applied to the conductors which connect with signaling conductors 300-304 for registration or recording purposes may be utilized to provide a visual display or record designation of the calling number.

In the description of the invention hereingiven, merely by way of illustrating its operation, it is assumed that a permanent record of the calling line number is desired and that this record is to be a printed one which can be produced by any commercially available printer such as, for instance, the one indicated by the rectangle 4%6. Those relays of the register which have operated apply ground to the common conductor 3&9 which connects with the winding of the start relay STI in the progress circuit and causes this relay to operate and start operation of said progress circuit, which may be of any suitable design, to complete circuits (not shown), whereby relays PT, TH, H, T, U, CL` and OFF are operated in the order given and whereby the succeeding relay is not operated until the preceding one is released, and whereby the interval during which each of said relays is maintained in anv operating position is sufcient to cause the performance of the registering or recording functions indicated below.

When, therefore, relay PT operates, in preparation to record the party designation, an obvious circuit is closed for start relay 415 in the` printer 406. Relay M5 operates to prepare said printer to receive the signal grounds applied to the signaling conductors 3M, 32 and 304 by the operated relay W or J of the party register circuit, which grounds cause the operation of two corresponding printer magnets to record the party designation. Following the release of relay PT by the progress circuit, the start relay M5 also releases to restore the printer.

Upon the operation of relay TH, the five sig-- naling conductors 30G-304 are connected to the relays ofthe thousands register and another obvious circuit is completed for start relay M5, whereupon the printer is caused to repeat the above operation for printing the thousands digit 8 in response to ground upon the conductors grounded by relay THS of the thousands register. Similar printing operations are performed upon the operation of relays T, U, CL and OFF, whereby the hundreds digit l, the tens digit 9, the units digit 0, the class digit 9 and the ofiice digit 2 are printed in response to ground applied selectively to the conductors Mii-3M by the tens, units, class and ofce registers.

When the entire number has been printed, relay 4I6 is operated in the printer, whereupon locking ground is removed from the relays locked in the registers, causing said relays to release and restore the registers to normal.

It is, of course, obvious that instead of using a progress circuit by means of which the group of signaling conductors for eachof the registers is switched into the printer circuit, theprogress circuit can be entirely dispensed with by running each group of conductors separately into the printer wherein means may be provided by which the various groups of conductors are cyclically connected to the printer magnets to print or perforate the numbers indicated thereon.

When the registering functions are completed, relay CONN is released, causing thereby the release of relay ST. The release of the register relays in response to the operation of relay M5 restores the operated register relays.

While I have described the principle of my invention in connection with its specific application to a particular telephone system and to a specic kind of gas-filled device, it is to be understood that various other applications and embodiments thereof may be made by those skilled in the art without departing from the spirit of the invention as defined within the scope of the appended claims.

What is claimed is:

l.. A line identification circuit for a telephone line having a numerical designation, comprising an electronic device individual to said line, means for activating said device, and means responsive to the activation of said device for registering the numerical designation of said line.

2. A line identication circuit for a telephone line having a multicharacter designation, comprising a gas-filled electronic device having a plurality of electrodes, one for each character of the designation, an anode connected to said line and a cathode, means responsive to said line initiating a call for rendering said gas-lled device conducting between its cathode and anode, means connected to each of said plurality of electrodes and responsive to the conductivity of the cathode and anode of said device for registering the multicharacter designation of said calling line.

3. A line identication circuit for a telephone line having a multicharacter designation consisting of a numerical identification, class of service identication and an oiice identification, comprising a gas-lled electronic device having a plurality of electrodes each corresponding to an element in said identication, an anode connected to said line and a cathode connected to one terminal of a source of potential, means responsive to said line initiating a call for connecting the other terminal of said source of potential to said anode over said line whereby said gas-filled device is rendered conducting between its cathode and anode and circuit means including sources of potential connected to said plurality of electrodes for registering the multidesignations of said line, said circuit means being rendered eiiective by the conductivity of said gas lled device over said plurality of electrodes subsequent to its initial conductivity between the cathode and anode.

4. An identification circuit for the lines of a telephone system comprising in combination a gas-filled electronic device for each line and a settable register common to all of said lines whereby a potential applied to any one of said lines operates its associated electronic device to set said settable register in accordance with the identity of said line.

5. An identification circuit for the lines of a telephone system comprising in combination a gas-filled electronic device for each line, a settable register common to all of said lines whereby a potential applied to any one of said lines operates its associated electronic device to set said settable register in accordance with the identity of said line, and means responsive to the setting of said register for disabling said operated gas-lled electronic device.

6. A line identification circuit for the twoparty lines of a telephone system, each of said lines having a multicharacter designation which includes the party designation, comprising a gaslled electronic device having a plurality of electrodes, one for each character of the designation, the anode of said tube being connected to a conductor of the line, means responsive to said line initiating a call for applying a potential between said cathode and anode for rendering said gas-lled device conducting therebetween, and means including a source of potential connected to said plurality of electrodes for rendering said gas-filled device conducting between its cathode and said plurality of electrodes whereby said means are operated to register the plural character designation of said line.

MARTIN E. MALONEY. 

